HbA1c, which is correlated with 3-month mean glycaemia, is usually measured every 36 months. Effects of variations of treatment are routinely assessed through HbA1c not earlier than 3 months. Glycated albumin (GA) has been proposed as an indicator of shorter-term (2-week) glucose control Aim of the present pilot study was to explore the possibility of predicting 3-month HbA1c by measuring HbA1c or GA at 1530 days. Twenty-seven metformin-treated patients with type 2 diabetes initiating a pharmacological treatment other than insulin were enrolled after written informed consent. The patients (16M:11F, aged 64.7±10.1 years) had a duration of diabetes of 8.6±8.5 years, baseline HbA1c 59.0±12.0 mmol/mol. The prescribed treatment was maintained throughout the 3-month follow-up. HbA1c and GA were measured at baseline, 15, and 30 days, and HbA1c only at 90 (±3) days. HbA1c at 90 days (50.0±7.2 mmol/mol) was significantly (P<0.001) reduced from baseline (59.0±12.0 mmol/mol). A significant reduction was already present at 15 days (56±7.8 mmol/mol, P<0.01) and confirmed at 30 days (53.0±7.0 mmol/mol, P<0.001). A similar pattern was found for GA, which was significantly lower at 15 (28.8±10.8%, P=0.03) and 30 (27.0±9.8%, P<0.001) days than at baseline (31.9±11.3%). Variations of both HbA1c and GA at 15 days showed a significant correlation with 90-day variation of HbA1c: R=0.895, P=0.001 and R=0.418, P=0.030, respectively, confirmed at 30 days. The early identification of patients not adequately responding to the prescription of a new drug could be very useful for clinicians, allowing a greater timeliness in further modifications of therapy. This pilot study suggests that a measurement of HbA1c as early as 15 days from the start of treatment can accurately predict 3-month results being of help for the assessment of treatment response. This result deserves to be further verified in larger samples.